Lasers have become widely used for industrial and medical applications. In many instances, the laser beam emitted by the laser apparatus is passed through a handpiece or other final delivery implement which is required to be manipulated so as to direct the laser beam in a precise manner. Various delivery system have heretofore been proposed, including both articulated booms and linear booms which are nonarticulated, the laser beam entering the proximal end of the boom, passing through the boom and into the proximal end of the handpiece.
Ayres U.S. Pat. No. 3,528,424 discloses a laser apparatus for use in surgery, there being provided a first right-angle conduit having a reflector at the angle and located about the arm connected to the laser housing, a second right-angle conduit rotatably connected to the second leg of the first right-angle conduit, and a linear boom connected at its proximal end to the second leg of the second right-angle conduit. The boom comprises first and second telescopic parts, the latter supported for rotational and longitudinal movement by a boom bearing comprising a pair of axially spaced ball bearings. At the distal end of the boom, a second joint made up of two right-angle conduits is provided, there being connected to the second leg of the second right-angle conduit a connection for a handpiece permitting rotation of the handpiece about an axis transverse to the second leg of the second right-angle conduit. A spring is connected to the outer part of the boom, for counterbalancing. This structure does not disclose a strong pivotal support for the proximal end of the boom, and provides a boom bearing which is somewhat resistant to movement, and therefore causes movement of the handpiece to be accomplished with more resistance to movement than is desirable, and there is provided a less than satisfactory counterbalancing system.
Vassiliadis U.S. Pat. No. 4,473,074 provides a surgical laser apparatus having a laser head supported by an articulated support arm system extending from a post. From the laser head, there extends a multi-section boom with a base section having a boom bearing formed by outer and inner tubes, the inner tube being supported for longitudinal and rotational movement by spaced apart groups of balls carried by a sleeve intermediate the two tubes. An intermediate boom section is connected to the base boom section by a joint permitting movement on an axis perpendicular to the boom base section axis, and a handpiece is connected to the intermediate boom section by a similar joint. The mounting of the boom to the laser head is fixed, no counterbalancing is shown, and the bearing, utilizing balls, offers more resistance than is desirable.
Sharon U.S. Pat. No. 3,913,582 provides a laser device which includes an optical bench having a laser within it, the bench being supported near one end on a post extending from a base cabinet. An upstanding shaft extends from the distal end of the optical bench, having a horizontally extending sleeve bearing on which is mounted a housing with a reflector in it, a longitudinally extending boom section being connected to the housing, and having at its distal end two right-angle conduits, with mirrors in them, the second conduit being connected to a second boom section which, at its distal end, has a triple right-angle conduit connection to a handpiece. A single counterbalance weight is provided on an arm which is supported on a horizontal pivot at the end of the shaft, one arm of the counterbalance engaging the first boom section, and the other arm supporting a counterweight. This apparatus does not have an axially extendable boom section, has no disclosure of the support structure for the proximal end of the boom, and has only a single counterweight to counterbalance all of the portions of the support arm system.
Karube et al U.S. Pat. No. 3,658,406 provides a laser beam guide apparatus in which a laser emitting device has a stationary boom connected to it, the boom having at its distal end a gear box to which a moving boom or handpiece is rotatably connected, there being a gear driven mirror within the gear box. The stationary boom contains a roller bearing permitting relative axial and rotational movement between two telescopic parts thereof. There is no disclosure of the mounting for the first boom section, which is rigidly fixed to the emitting device, the boom bearing has more friction than is desirable, and no counterbalancing is provided.
Galan U.S. Pat. No. 4,623,229 provides an articulated laser arm apparatus for use with a robot, for industrial purposes. A four-section boom is connected to a laser; the first and second sections are fixed. The second section is rotatably connected by a right-angle joint to the third section, and the third section is rotatably connected by a pair of right-angle joints to the fourth section, with a pair of mirrors therein. The distal end of the fourth section is connected to a pair of right-angle joints, utilizing three reflectors, to the last of which is connected a laser delivery instrument guided by a robot. A counterbalance mechanism is provided comprising a pair of spaced apart bunges (counterbalance springs) which are connected at their lower ends to the fourth section of the boom, and at their upper ends to a fixed support. This construction requires multiple articulated boom sections, there is no extendable boom section, and the counterbalancing is effective only with regard to the entire mass of the boom, starting with the third section and to the utilization implement, so that counterbalancing is less exact than is desirable for a hand held utilization implement or handpiece.